//摆动序列

class Solution {
public:
    int wiggleMaxLength(vector<int>& nums) {
        int n = nums.size();
        vector<int> f(n, 1);
        vector<int> g(n, 1);
        int ret = 1;
        for(int i = 1; i < n; i++)
        {
            for(int j = 0; j < i; j++)
            {
                if(nums[j] < nums[i])
                {
                    f[i] = max(f[i], g[j] + 1);
                }
                if(nums[j] > nums[i])
                {
                    g[i] = max(g[i], f[j] + 1);
                }
            } 
            ret = max(ret, max(f[i], g[i]));      
        }
        return ret;
    }
};